Virtual Private LAN Services
7210 SAS-X, R6 OS Services Guide Page 377
The no form of this command returns the edge port setting to the default value.
Default no edge-port
forward-delay
Syntax forward-delay seconds
no forward-delay
Context config>service>vpls>stp
config>template>vpls-template>stp
Description RSTP, as defined in the IEEE 802.1D-2004 standards, will normally transition to the forwarding state
via a handshaking mechanism (rapid transition), without any waiting times. If handshaking fails (e.g.
on shared links, see below), the system falls back to the timer-based mechanism defined in the
original STP (802.1D-1998) standard.
A shared link is a link with more than two nodes (for example, a shared 10/100BaseT segment). The
port-type command is used to configure a link as point-to-point or shared.
For timer-based transitions, the 802.1D-2004 standard defines an internal variable forward-delay,
which is used in calculating the default number of seconds that a SAP spends in the discarding and
learning states when transitioning to the forwarding state.
The value of the forward-delay variable depends on the STP operating mode of the VPLS instance:
• in rstp or mstp mode, but only when the SAP has not fallen back to legacy STP operation, the
value configured by the hello-time command is used;
• in all other situations, the value configured by the forward-delay command is used.
Default 15 seconds
Parameters seconds — The forward delay timer for the STP instance in seconds.
Values 4 — 30
hello-time
Syntax hello-time hello-time
no hello-time
Context config>service>vpls>stp
config>template>vpls-template>stp
Description This command configures the Spanning Tree Protocol (STP) hello time for the Virtual Private LAN
Service (VPLS) STP instance.
The hello time parameter defines the default timer value that controls the sending interval between
BPDU configuration messages by this bridge, on ports where this bridge assumes the designated role.
The active hello time for the spanning tree is determined by the root bridge (except when the STP is
running in RSTP mode, then the hello time is always taken from the locally configured parameter).
The configured hello-time can also be used to calculate the forward delay. See auto-edge on page 376.
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